Elon Musk has become embroiled in an intellectual property row after telling an artist it would be “kinda lame” if he sought compensation over allegations Tesla reproduced his work without permission.

The Tesla CEO tweeted a photo of an original mug by Colorado artist Tom Edwards in February last year, saying the piece of pottery, which featured a cartoon of a unicorn farting electricity, was “maybe my favorite mug ever.”

The billionaire’s admiration for the image seemingly grew as it later appeared on https://twitter.com/elonmusk/status/847259545755820033 material for a new sketchpad feature, as a small icon on the car’s operating system, and was even used on a company Christmas card. When Tesla failed to respond to a letter from Edwards asking for a consultation to discuss compensation, the potter’s daughter, Lisa Prank, took to Twitter to raise the issue with Musk directly.

Amazingly, Musk responded, saying Edwards “can sue for money if he wants, but that’s kinda lame,” and claimed his intervention boosted the artist’s sales. “I popularized your Dad’s mug for free, he made thousands of dollars as a result & now he wants more money because someone else’s drawing of that mug was used as a sketch pad example in a *hidden* feature,” Musk wrote.

Prank claimed the issue was one of “stolen intellectual property” and called on the tech tycoon to engage with her father’s lawyer to reach a settlement.

In a later series of tweets, Musk called an article purporting to detail the dispute “BS” and said he twice offered to pay the artist “for something we don’t even want.” He then claimed to “definitely care about artists getting compensated. It would be unfair not to do so.” Finally, replying to one commentator’s plea to “stop freeloading,” Musk said: “Too bad, I’m stealing his mug crayon drawing.”